Power Consumption: ESXi Home Lab

One of the bigger questions that I’ve always gotten about my builds is what is my energy consumption. That’s something I’ve always been able to estimate, however, I’ve never taken the time to actually watch the wattage load with my Kill-a-Watt, or anything else. Primarily because my lab is also a production lab, it very rarely comes down for any amount of time. Last night gave me that opportunity.

Battery Backup for ESXi: APC BR1500G and APC BR24BPG

My lab had been running on an older, rackmount UPS that I had picked up off eBay, and although a solid UPS, it was feeling its age, and most likely needed some new batteries. Instead, I decided to upgrade, and caught a couple of items on sale at Amazon: the APC BR1500G BACK-UPS Pro 1500 and APC BR24BPG Back-UPS Pro External Battery Pack that goes with it. Although I don’t have a lot of power losses here, ESXi does take some time to suspend everything and get shut down properly, so I wanted a long run time. These fulfilled that, and admirably.

Power Consumption on ESXi Home Lab Builds

Building out my home lab, I had a number of “rules” that had to be met before a build was successful for the nodes. The list is below, but one of those was simply that it had to be energy efficient. I can go on eBay and pick up Dell 2950s all day long cheap … but they are power hungry beasts, and the resulting electric bill will far out-strip any savings that I find.

Nodes must use consumer grade hardware that also allow access to PCI Passthrough, Fault Tolerance, vMotion, and all other extended ESXi abilities, or server-grade hardware that is cheap and easily aquired (such as the Intel Pro/1000 Dual Gigabit PCI-X network cards I use)

Hardware must be easy to acquire

Nodes must be energy efficient. Idle wattage ideally needs to be <150 watts

Discovering ESXi Energy Consumption with APC PowerChute Software

APC includes a piece of software for free with their UPS Battery Backups that monitors your energy usage. It will even allow you to input your cost per kw/H and it will give you the cost per month (the longer it runs, the better) that everything hooked up to it costs. In addition, it will shut your computer down when it’s low on power. You can also set this up to automatically suspend your VMs and shut down your ESXi nodes, but that’s for another article.

The APC series of UPS come with a data cable that allows you to plug into a USB port and monitor the UPS, as I said. In my case, I have it monitored by my standalone vCenter/Starwind iSCSI box, since this box is doing little beyond that work. The box is running the cheapest AMD dual-core CPU, and still doesn’t have any issues performing it’s assigned workload.

Power consumption for the node was almost spot on to my calculations, with the node idling at 121 watts. One thing to remember is that this IS idle. Although your consumption wouldn’t go up much at full load, if you’re folding or number crunching 24/7, you’ll see a difference on your electric bill that you’ll need to be aware of.

Power Consumption: ESXi Home Lab Node

Power consumption with the entire node online was right around my calculations also. The Dell DGS-1124T 24-Port Gigabit Smart Switches are green and draw around 9 watts each, the modem and router draw about the same, and even my primary ESXi node which has a large number of hard drives in it, only draws about 50w more than this. You can see that build at ESXi 5.0 AMD Whitebox Server for $500 with Passthrough (IOMMU)

The entire lab idles at just under 600 watts. I consider that a success for 32 cores, 128GB of RAM, three ESXi nodes, two firewalls, two 24-port gigabit switches, and a standalone vCenter box that also functions as a iSCSI node. At my current cost of .09 per killowatt hour, that puts my cost at $1.296 per day, $38.88 per month, or $473.04 per year.

Thank you, Don, for sharing theses specs. I’ve been planning to make a few changes to my home network and would like to apply some of the concepts you’ve put in place. It would not be as much of a full-blown lab as you have deployed, but I think it’ll do the job.

I’ll share my setup (as soon as I define it), and see what you think of it.

Don Fountain

The HomeServerBlog.com is information about using real datacenter technologies in your home, configured in an easy to maintain, efficient, and most of all, cost effective manner. We focus on helping you with a lab that is multiuse, allowing for experimentation with virtualization and other technologies, home storage, home backup, and more.
Note that my posts are my opinion, and not any official view or stance of my employer. About Me